1. Field of the Invention
Embodiments of the present invention generally relate to a method and an apparatus for recycling an electrochemical mechanical polishing (ECMP) fluid.
2. Description of the Related Art
ECMP is a technique used to remove conductive materials from a substrate surface by electrochemical dissolution while concurrently polishing the substrate with reduced mechanical abrasion compared to conventional planarization processes. ECMP systems may generally be adapted for deposition of conductive material on the substrate by reversing the polarity of the bias. Electrochemical dissolution is performed by applying a bias between a cathode and a substrate surface to remove conductive materials from the substrate surface into a surrounding electrolyte. The bias may be applied to the substrate surface by a conductive polishing material on which the substrate is processed. A mechanical component of the polishing process is performed by providing relative motion between the substrate and the conductive polishing material that enhances the removal of the conductive material from the substrate.
During ECMP processing, ECMP fluid may be provided to the ECMP system to process the substrate. The ECMP fluid may be continuously recirculated to the platen during polishing and then drained and discarded once processing is completed. Therefore, there is a need in the art for a method and apparatus for providing ECMP fluid to an ECMP system for polishing substrates.